This invention relates generally to supply hubs for use on a supply reel in a reel to reel computer tape drive and more particularly to a new and novel supply hub for a supply reel which assures locking of the supply reel onto the supply hub. Computer tape drives which are positioned in an upright manner for access to the computer tapes or in a horizontal configuration for a maximum number of tapes in a minimum area have long been used in the computer industry. Generally, the magnetic tape supply reel is secured to a supply hub and the free end of the supply reel tape is threaded past a head and then secured to a take up reel which is attached to a take up hub.
In order to facilitate the securing of the supply reel onto the supply hub, there have been used supply hubs with reel engaging pawls, a centering knob and a single sensing mechanism for determining if the supply reel is centered and secured onto the supply hub. One such supply reel is disclosed in U.S. Pat. No. 4,243,186, manufactured by Cipher Data Products, Inc. of San Diego, Calif. Such supply hubs have several problems. First, it often appears at first glance that the supply tape reel is properly positioned and aligned on the supply hub, when, in fact, it is not. One side of the supply reel may be properly positioned against the supply hub and has been sensed as being in position while the other side of the supply reel is not properly aligned. Secondly, the centering knob does not allow for the mounting of six-inch reels as the inner hub of the six-inch reels cannot be positioned over the centering knob. Furthermore, in the case where the supply reel is not properly positioned on the supply hub, there is no error message transmitted to the computer or computer tape drive, rotation of the tape is continued, often resulting in tape damage. It has also been encountered that when the supply reel has a write enable ring with a tab on it, upon loading of the supply reel onto the supply hub, the tab may become caught on the centering knob.
Consequently, it would therefore be advantageous to have a supply reel hub which would assure locking of the supply reel onto the supply hub in order to prevent tape damage and for safety reasons.